Special variables -- $STACK


Introduced in the 1995 ANSI M[UMPS] language standard.

This variable indicates the current execution stack depth (DO level).
The difference between $STACK and $ESTACK is that $ESTACK may appear as an argument of the NEW command. NEWing $ESTACK resets its value to 0 (zero), and can be useful to set up a layered error trapping mechanism.

The value of $STACK is "absolute" since the start of the M[UMPS] process, whereas the value of $ESTACK is "relative" to the most recent "anchoring point".

For examples of the use of special variable $STACK, see the function $STACK.

This document is © Ed de Moel, 1995-2005.
It is part of a book by Ed de Moel that is published under the title "M[UMPS] by Example" (ISBN 0-918118-42-5).
Printed copies of the book are no longer available.

This document describes the various special variables that are defined in the M[UMPS] language standard (ANSI X11.1, ISO 11756).

The information in this document is NOT authoritative and subject to be modified at any moment.
Please consult the appropriate (draft) language standard for an authoritative definition.

In this document, information is included that will appear in future standards.
The MDC cannot guarantee that these 'next' standards will indeed appear.